A December Bug Bonanza

Submitted by Bill Dunson on Wed, 12/12/2012 - 1:32pm

What defines beauty- the eye of the beholder or perhaps our genes? A sunrise photo elicits pleasure for most of us and we can agree that it is beautiful. This is not so for most insects even though they may have amazing colors and shapes. As a naturalist I find it impossible to ignore insects since they are so numerous and have very remarkable life histories. They are difficult to deal with since there are so many types, some unfamiliar to us. But with a little effort you can begin to learn the common species in your habitat and you will be richly rewarded since this knowledge opens up a panorama of ecological interactions and natural patterns that are often hidden from us. Just consider a few insects that I encountered recently in early December in SW Florida.

Bill Dunson

Sunrises and sunsets are free so why don't we enjoy such simple pleasures of life more?

Bill Dunson

This adult tiger moth advertises its toxicity with flash colors on the abdomen and legs

Bill Dunson

This male scarab beetle uses its rhino horns to fight with other males for dominance

Bill Dunson

The larval form of the ox beetle is a large grub that lives underground and eats plants

Bill Dunson

This sculptured pine borer feeds on pines and can be considered a pest by tree farmers

Bill Dunson

This twilight darner is a ferocious predator on small flying insects

Bill Dunson

This small Cassius blue is resting on a cow pea which supplies it with nectar

Bill Dunson

This queen butterfly has found a slit in the base of this Cape Honeysuckle flower that allows it to steal some nectar

Bill Dunson

This monarch is obtaining nectar from the very small and inconspicuous flowers of Florida privet

Bill Dunson

Male blue crabs recognize females by the bright red "lipstick" on their claws

The salt marsh caterpillar moth is widely distributed from Canada to Texas and I often encounter the caterpillars feeding on dog fennel. This moth is the first adult I have seen in Florida and it was attracted to our window light at night. They are known to use plant toxins to protect themselves and the defensive display of this moth is striking as it reveals orange areas that are normally hidden. The life story of this moth reveals that dog fennel contains dangerous toxins and should not be eaten by humans.

A common but rarely seen scarab beetle is the large ox beetle. It is a "rhino" beetle since the male has three horns which are used in male to male combat. The grub larvae of this beetle are commonly found in sandy soils where they leave small mounds of sandy pellets. Both moles and white ibis relish these large grubs and provide biological control when these beetles occur in lawns.

An interesting beetle was encountered at Wildlfower Preserve when it landed on the dark shirt of a hiker- it is the sculptured pine borer. This is a general pest on various pine species. Adults feed on young buds and leaves and the larvae bore in decaying wood. If you are growing pines for profit they can be a nuisance, but they are a useful part of the community of animals that participate in the turnover of tree biomass in forests. Woodpeckers likely have a different opinion of this bird food than humans do.

Insects that can be considered very beneficial to humans are the dragonflies, since they eat other insects including injurious species such as mosquitoes and flies. Because of their rapid movements they can be hard to appreciate but it is becoming popular to study them with binoculars and learn the common species. This large twilight darner flew into a window and I was able to catch it for a moment and appreciate the beauty of its form- the amazing wings, large eyes and strong jaws which it used to bite me. All dragonfly larvae are aquatic and thus live totally different lives from their parents- an adaptation that avoids competition between juveniles and adults.

One group of insects that humans find very attractive are the "flying flowers," the butterflies. Yellow cow pea flowers are in bloom now and are attracting many small blue butterflies. This Cassius blue is a tiny marvel which is restricted to far southern climates. The local milkweed butterflies are much easier to identify but still somewhat confusing. A queen is shown here getting nectar from a slit in the base of a Cape honeysuckle flower. These gorgeous flowers are native to S. Africa and local butterflies are not suited to obtain nectar through the "front door" of the flower corolla tube; instead this crafty butterfly is using a hole in the base of the flower, possibly made by a bee, to use the "back door" to steal nectar. Since pollination does not occur, the flower will not benefit as it would if S. African sunbirds drank from the front of the corolla tube. Another surprising sight is a monarch obtaining nectar from the tiny flower of Florida privet. This is unexpected since the flowers do not seem to be designed for attracting large butterflies and indeed are mainly visited by bees and wasps. If you observe butterflies visiting flowers you will soon come to realize that they are more flexible in their behavior than the insect automatons we may think they are.

Finally I offer a short story about blue crabs, which obviously are not insects, but as crustaceans are sister arthropods. The female has red claw tips which might seem to be pretty but of limited general interest. However it has been found that if you paint these claws black, the males have no interest in mating with them. So suddenly you realize that this is "lipstick on a crab." It has become a common theory that many genes in humans have their origins in very early stages of animal evolution. I have often wondered why of all things, human females started coloring their lips red with plant pigments to enhance heir sexual attractiveness. Isn't it amusing that a very primitive animal such as the crab basically does the same thing?

So BUGS RULE! It is thus in our interest to keep an eye on insects for our potential benefit. But a far greater reason to learn about invertebrates is just because they are incredibly diverse, fascinating and beautiful.